Metals used in the form of free metal or metal compounds in electrical components, such as batteries and conductors are often expensive to obtain and the recycling thereof can have economic value. Because metal and metal compounds can be corrosive, highly reactive or hazardous to plants and animals, there can be environmental value in recycling of these materials found in electrical components.
Although there has been some attempt to recycle lead acid batteries in the past, complex electrical components have not traditionally been recycled because of the logistics of concentrating a sufficient amount of recyclable electrical components in a single location and the hazards and potential complexity of the process technology. This is particularly the case when the electrical component to be recycled contains a material like lithium in metallic form which could be explosive.
Solid-state electrochemical cells are typically constructed from an alkali metal negative electrode (anode), an ionically conducting polymeric electrolyte containing an ionizable alkali metal salt, and a positive electrode (cathode). The cathode is usually formed by preparing a mixture of an active material, a metal salt, a polymeric electrolyte, and a conductive filler such as carbon black, and coating this mixture on a metal foil which functions as a current collector. Electrochemical cells formed in this fashion using lithium metal as the alkali metal anode have found wide use in numerous applications requiring portable battery power, since lithium batteries formed in this manner have a high energy density.
However, lithium metal is widely considered to be the major source of safety-related problems when lithium batteries are made rechargeable. Charging of such batteries converts lithium ions to metallic lithium, and the presence of metallic lithium in the recycle of the battery structure can result in explosion.